Touch-sensitive devices generally provide for identification of positions where the user touches the device, including movement, gestures, and other effects of position detection. For a first example, touch-sensitive devices can provide information to a computing system regarding user interaction with a graphical user interface (GUI), such as pointing to elements, reorienting or repositioning those elements, editing or typing, and other GUI features. For a second example, touch-sensitive devices can provide information to a computing system suitable for a user to interact with an application program, such as relating to input or manipulation of animation, photographs, pictures, slide presentations, sound, text, other audiovisual elements, and otherwise.
Some touch-sensitive devices are able to determine a location of touch, or multiple locations for more than one touch, using sensing devices that are additional to those sensing devices already part of the touch-sensitive device.
Generally, however, touch is binary. The touch is present and sensed, or it is not. This is true of many user inputs and input/output devices. A key of a keyboard, for example, is either pressed sufficiently to collapse a dome switch and generate an output signal, or it is not. A mouse button is either pressed sufficiently to close a switch, or it is not.